# HG changeset patch
# User kaf24@xxxxxxxxxxxxxxxxxxxx
# Node ID d0f23c103453015931a435321deeceafa91560d5
# Parent 0608852073c86cfa432ac32cb9223531950be896
Six the SWIOTLB. The bus range does need to be contiguous after
all as a range comparsion is used to determine if a given
dma address is within the swiotlb aperture.
Maybe we can do better sometime in the future (fast address
range comparison yet not require bus-contiguous aperture). But
reverting this morning's patch is fine for now.
Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>
diff -r 0608852073c8 -r d0f23c103453
linux-2.6-xen-sparse/arch/xen/i386/kernel/swiotlb.c
--- a/linux-2.6-xen-sparse/arch/xen/i386/kernel/swiotlb.c Fri Aug 19
17:25:04 2005
+++ b/linux-2.6-xen-sparse/arch/xen/i386/kernel/swiotlb.c Fri Aug 19
17:51:37 2005
@@ -43,20 +43,18 @@
#define IO_TLB_SHIFT 11
int swiotlb_force;
+static char *iotlb_virt_start;
+static unsigned long iotlb_nslabs;
/*
* Used to do a quick range check in swiotlb_unmap_single and
* swiotlb_sync_single_*, to see if the memory was in fact allocated by this
* API.
*/
-static char *iotlb_virt_start, *iotlb_virt_end;
-static dma_addr_t iotlb_bus_start, iotlb_bus_end;
-
-/*
- * The number of IO TLB blocks (in groups of 64) betweeen iotlb_virt_start and
- * iotlb_virt_end. This is command line adjustable via setup_io_tlb_npages.
- */
-static unsigned long iotlb_nslabs;
+static dma_addr_t iotlb_bus_start, iotlb_bus_mask;
+
+/* Does the given dma address reside within the swiotlb aperture? */
+#define in_swiotlb_aperture(a) (!(((a) ^ iotlb_bus_start) & iotlb_bus_mask))
/*
* When the IOMMU overflows we return a fallback buffer. This sets the size.
@@ -94,6 +92,9 @@
iotlb_nslabs = simple_strtoul(str, &str, 0) <<
(20 - IO_TLB_SHIFT);
iotlb_nslabs = ALIGN(iotlb_nslabs, IO_TLB_SEGSIZE);
+ /* Round up to power of two (xen_create_contiguous_region). */
+ while (iotlb_nslabs & (iotlb_nslabs-1))
+ iotlb_nslabs += iotlb_nslabs & ~(iotlb_nslabs-1);
}
if (*str == ',')
++str;
@@ -120,6 +121,9 @@
if (!iotlb_nslabs) {
iotlb_nslabs = (default_size >> IO_TLB_SHIFT);
iotlb_nslabs = ALIGN(iotlb_nslabs, IO_TLB_SEGSIZE);
+ /* Round up to power of two (xen_create_contiguous_region). */
+ while (iotlb_nslabs & (iotlb_nslabs-1))
+ iotlb_nslabs += iotlb_nslabs & ~(iotlb_nslabs-1);
}
bytes = iotlb_nslabs * (1UL << IO_TLB_SHIFT);
@@ -133,17 +137,12 @@
"Use dom0_mem Xen boot parameter to reserve\n"
"some DMA memory (e.g., dom0_mem=-128M).\n");
- for (i = 0; i < iotlb_nslabs; i += IO_TLB_SEGSIZE)
- xen_create_contiguous_region(
- (unsigned long)iotlb_virt_start + (i << IO_TLB_SHIFT),
- get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT));
-
- iotlb_virt_end = iotlb_virt_start + bytes;
+ xen_create_contiguous_region(
+ (unsigned long)iotlb_virt_start, get_order(bytes));
/*
* Allocate and initialize the free list array. This array is used
- * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
- * between iotlb_virt_start and iotlb_virt_end.
+ * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE.
*/
io_tlb_list = alloc_bootmem(iotlb_nslabs * sizeof(int));
for (i = 0; i < iotlb_nslabs; i++)
@@ -156,15 +155,19 @@
* Get the overflow emergency buffer
*/
io_tlb_overflow_buffer = alloc_bootmem_low(io_tlb_overflow);
+
iotlb_bus_start = virt_to_bus(iotlb_virt_start);
- iotlb_bus_end = iotlb_bus_start + bytes;
+ iotlb_bus_mask = ~(dma_addr_t)(bytes - 1);
+
printk(KERN_INFO "Software IO TLB enabled: \n"
" Aperture: %lu megabytes\n"
" Bus range: 0x%016lx - 0x%016lx\n"
" Kernel range: 0x%016lx - 0x%016lx\n",
bytes >> 20,
- (unsigned long)iotlb_bus_start, (unsigned long)iotlb_bus_end,
- (unsigned long)iotlb_virt_start, (unsigned long)iotlb_virt_end);
+ (unsigned long)iotlb_bus_start,
+ (unsigned long)iotlb_bus_start + bytes,
+ (unsigned long)iotlb_virt_start,
+ (unsigned long)iotlb_virt_start + bytes);
}
void
@@ -444,7 +447,7 @@
int dir)
{
BUG_ON(dir == DMA_NONE);
- if ((dev_addr >= iotlb_bus_start) && (dev_addr < iotlb_bus_end))
+ if (in_swiotlb_aperture(dev_addr))
unmap_single(hwdev, bus_to_virt(dev_addr), size, dir);
}
@@ -463,7 +466,7 @@
size_t size, int dir)
{
BUG_ON(dir == DMA_NONE);
- if ((dev_addr >= iotlb_bus_start) && (dev_addr < iotlb_bus_end))
+ if (in_swiotlb_aperture(dev_addr))
sync_single(hwdev, bus_to_virt(dev_addr), size, dir);
}
@@ -472,7 +475,7 @@
size_t size, int dir)
{
BUG_ON(dir == DMA_NONE);
- if ((dev_addr >= iotlb_bus_start) && (dev_addr < iotlb_bus_end))
+ if (in_swiotlb_aperture(dev_addr))
sync_single(hwdev, bus_to_virt(dev_addr), size, dir);
}
@@ -610,7 +613,7 @@
size_t size, enum dma_data_direction direction)
{
BUG_ON(direction == DMA_NONE);
- if ((dma_address >= iotlb_bus_start) && (dma_address < iotlb_bus_end))
+ if (in_swiotlb_aperture(dma_address))
unmap_single(hwdev, bus_to_virt(dma_address), size, direction);
}
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